Improvement in engine-lathes



W. T U C KE R;

ENGINE-LATHE.

Patented Nov. so 1875.

INVENTOR WW By ttm'neys wlT'NEssEs UNITED STATES PAT NT OFFICE.

WILLIAM TUCKER, OF FISKEDALE, MASSACHUSETTS.

IMPROVEMENT IN ENGlNE-LATHES.

Specification forming part of Letters Patent No. 170,605, dated November30,1875 application filed May 17, 1875.

To all whom it may concern Be it known that I, WILLIAM TUCKER, ofFiskedale, in the county of Worcester, in the State of Massachusetts,have invented a new and useful Improvement in Engine-Lathes, of

which the following is a specification:

The objects accomplished by this invention have reference to theoperation of cutting screws in engine-lathes.

My presen invention consists in means for giving to enginelathes thecapacity of cutting screws in a longer range of pitches than hasheretofore been practicable, and this without any corresponding increaseof gearing or complication of parts, and to an extent that could not, asI believe, be practically accomplished in the usual wayt'. 6., by changeof gears of different numbers of teeth, as hereinafter set forth.

Figure 1 is a plan view of so much of a lathe-head of recent andapproved pattern as is necessary to illustrate this invention embodiedtherein. Fig. 2 is a verticallongitudinal section of the same. Fig. 3 isa sectional elevation, showing the novel features of construction on alarger scale. Fig. 4 is a transverse section on the line 4. 4, Fig. 3.

w The sections represented in Figs. 2 and 3 are on the lines 2 2 and 33, Figs. 1 and 4..

H represents the housing of the lathe-head S, the primary spindle; S thesecondary spindle; S, a sleeve-shaft on the latter; P,

the cone-pulleys or cone on the primary spindle, andA B G D E the gears.Of these, the first four gears, A B O D, are employed for back-gearingin ordinary manner. The first gear A is attached to the cone andtransmits its motion to the second and third, B O, which are fast on thesleeve-shaft S The third gear 0 transmits the motion to the fourth, D.which is fast on the primary spindle S. The transmitting-gears A U aresmall and of equal size, each .having twenty-six teeth. The two largerones B D are also equal and have seventy-eight teeth each. This causeseach pair of gears to slow the motion and increase the power threetimes. From the cone to the lathe-spindle there is, consequently, amultiplication of nine times the power imparted to the cone, while thelatter has ninefold greater speed than the spindle.

The back gears are thrown into and out of mesh by means of alever-handle, L, on the secondary spindle S which is an oscillatingeccentric. I

To provide for driving the primary spindle at the same speed as thecone, the gear D,

screw of a screw-cutting lathe. This feedgear is common to allengine-Lathes; but heretofore it has been made fast to the primaryspindle on which it is mounted, so as to have always the same speed asthe spindle.

The objects of the present invention are accomplished by adapting thisgear to. be at-- tachcd at will to the primary spindle or to the conedirect.

In the illustration a flanged bushing, F, is made fast to the spindle atthis point, and the feed-gear is adapted to slide thereon. The gear isprovided with a clutch-pin, a, projecting at each end, the bushing witha correspondingly-perforated flange, b, and the cone-gear A with acorresponding hole, 0.

An annular chamber, d, Fig. 4, is formed within the feed-gear. Aspring,e, made in the form of a divided ring, and carrying a V- shapedhead or detent, f, is arranged in this .chamber, and a pair ofcircumferential V- grooves, g g are out in the periphery of the "sleeveof the bushing F, to receive the detent f, for holding the feed-gear inits different positions on the bushing. The V shape of the detent adaptsit to rise out of the respective grooves when end pressure is applied tothe feed-gear for shifting it.

When the feed-gear is shifted so as to throw its pin va into the hole inthe flange b, it is madefast to the spindle. When it is slid so as tothrow its pin into the hole 0 it is made fast to the cone. This movementof the feedgear can always be made when the cone and large spindle-gearare locked together, as then the pin of the foedgear is in line withboth holes. When the feed-gear is attached to the cone-gear it isapparent that it is not backgeared with the spindle, but is drivendirectly by the belt without change by the back gears, although they maybe in mesh so as to back-gear the spindle. This is what it is desirableto accomplish, as in cutting coarse screws the spindle must have acomparativelyslow motion, while the movement of the toolcarria-ge mustbe relatively fast. When the feed-gear is attached to the flangedbushing the lathe will do all and no morethan an ordinary lathe. Supposeits capacity of pitches in this condition to be two, three, four, five,

six, seven, eight, nine, ten, twelve, thirteen,

fourteen, sixteen, eighteen, twenty, twentytwo threads per inch. Now, bysimply shifting the feed-gear, so as to attach it to the conegear, anadditional range of pitches is obtained, as follows: two-ninths,three-ninths,

four ninths, five ninths, six ninths, sevenninths, eight-ninths,nine-ninths, ten-ninths,

twelveninths, thirteen-hi nths,fourteen-ninths, sixteen-ninths,eighteen-ninths, twen ty-ninths, twenty-two-ninths threads per inch.This is owing to the relative speeds of the cone and the back-gearedspindle, which are nine to one in the illustration.

It will he observed that no gears are employed in addition to thosewhich are essential to the first result, and the only additional piecesare the appurtenances of the sliding Any preferred means may be usedlt-oconvey the motion from the teed-gear to the various kinds of feedmechanism, andto the.

leadingscrew. i

It is deemed impracticable to get the pro posed range of pitches bymultiplying gears,

first, because the requisite room could not be afforded, and, secondly,because too much power would be lost by friction in gearing down for thework, and up again for the feed to the required extent for coarsethreads and spiral cutting.

This invention renders possible ona lathe a kind of work that has notbefore been done in this way: The work may have a slow rotation, whilethe cutting-edge of the tool moves with relative rapidity parallel toits axis.

The coarsest cut of-thread inthe scales spindle or to the cone direct,as herein de scribed, for the purpose specified.

3. The bushing F, having the perforated flange I) and groove 9 g ,thespringe, having the detent-head f, the double-ended clutchr pin a, andthe clutch-hole c in the cone-gear A, in combination' with the primaryspindle, cone, and feed-gear of an en gine-lathe, as here: in shown anddescribed, for the purposes set forth.

WILLIAM TUCKER.

Witnesses:

EMORY L. BATES, R. E. BOND.

